1. Technical Field
The present invention relates to a semiconductor device and a semiconductor device fabrication method.
2. Related Art
Heretofore, when a resistance element is to be formed in an integrated circuit of a semiconductor device, for example, a polysilicon layer is formed and then the resistance thereof is adjusted by doping the polysilicon layer with impurities to form the resistance element (for example, see Japanese Patent Application Laid-Open (JP-A) No. 2005-142531). Thus, the resistance value is controlled by an amount of impurities in the polysilicon layer.
However, because the resistance value of the polysilicon layer is controlled by the amount of doped (implanted) impurities, when resistance elements with different resistance values are to be produced, a mask for impurity doping (known as an implantation mask) must be prepared for each target resistance value, and the impurities injected into the polysilicon layer using the respective masks for impurity doping such that different impurity amounts result. This situation causes costs.